This invention relates generally to complex real time systems in wireless communications, and more particularly to a method for dynamically managing the priority of system algorithms to achieve optimal efficiency.
The following are expansions for certain acronyms used in this application:
SCC slow congestion control
F-DCA fast dynamic channel allocation
LM link maintenance
C-RNC controlling radio network controller
There is an ever-increasing need to achieve enhanced efficiency of operation in complex communication systems, and, the need is even greater in management of real time systems that use a plurality of algorithms.
In complex real-time systems, it is desirable to use priority-handling mechanisms on processes to achieve optimal efficiency. The RRM (Radio Resource Management) algorithms fall into the above category. Traditional fixed-priority handling mechanisms work well in small and stable systems. However, the wireless communication environment is very dynamic and complex. It is necessary and beneficial that the execution priority of the algorithms can be changed according to the most current system status.
Prior art offers information in patent publications that deal with operating system scheduling and packet scheduling, for example. The following are examples of U.S. patents generally in the field of networks:
In U.S. Pat. No. 6,453,360, titled xe2x80x9cHigh Performance Network Interfacexe2x80x9d, a high performance network interface is provided for receiving a packet from a network and transferring it to a host computer system. A header portion of a received packet is parsed by a parser module to determine the received packet""s compatibility with, or conformance to, one or more pre-selected protocols. Packets are stored in multiple queues with priorities.
U.S. Pat. No. 6,452,915, titled xe2x80x9cIP-flow Classification in a Wireless Point To Multi-Point (PTMP) Transmission Systemxe2x80x9d, is directed to an IP-flow classification system used in a wireless telecommunications system. More specifically, the IP flow classification system in said U.S. patent provides for grouping IP-flows from a packet-centric wireless point to a multi-point telecommunications system. A quality of service (QoS) grouping device therein may include an optional differentiated services (Diff-Serv) device that takes into account an optional Diff-Serv field priority-marking for the IP-flow.
In U.S. Pat. No. 6,449,251, titled xe2x80x9cPacket Mapper for Dynamic Data Packet Prioritizationxe2x80x9d, a packet-mapper maps streams of data packets in a computer network, each data packet having a packet header containing feature values descriptive of the data packet. The packet-mapper includes a mapping table that associates application-related feature values with network-reserved feature values from a range of feature values reserved for use by selected network data packet streams. Prioritization in said U.S. patent is achieved by assigning a port-number for packets.
The above examples of U.S. patent publications are, however, not directly applicable to management of and scheduling between different RRM algorithms, and do not take into account system status.
It is desirable to provide a method of dynamically managing system algorithms, e.g., RRM algorithms, so as to achieve optimal efficiency.
The present invention provides a method of dynamically managing system algorithms in wireless communications, considering system status in real time. The present invention recognizes that in general, in complex real-time systems such as wireless systems, it is very desirable to use priority-handling mechanisms on the processes to achieve optimal efficiency. RRM is a collection of relatively independent algorithms whose common purpose is to manage the scarce radio resources efficiently. For example, although the purpose of each RRM algorithm may be somewhat independent of the other, the algorithms may end up acting on similar objects (e.g., one algorithm may want to reduce the rate of the link, whereas another may want to move it to another timeslot). To achieve optimal results, the algorithms should be executed in a timely manner. However, it is not efficient for the algorithms to be running at the same time trying to solve the same problem. Moreover, the best solution at one time may not be the best solution at another time due to the quick and unpredictable changes of system status and system-performance in the wireless environment.
The present inventive method of dynamic priority management provides an efficient way to prioritize different algorithms in a fast changing environment. It can be applied to, but is not limited to the RRM system. The inventive method is general and targets different types of complex and dynamic real-time systems.
As described hereinafter, a preferred embodiment provides a method for dynamic priority management of system algorithms. It is especially suitable for large, complex and dynamic systems such as wireless communication systems. Specifically, the following aspects of the inventive method are addressed hereinafter:
a) when to increase or decrease algorithm priorities,
b) how to increase or decrease algorithm priorities,
c) how to assign priority parameters, and
d) how to dynamically manage priorities in the system.
The inventive method provides at least the following advantages:
avoidance of the higher priority algorithms always triggering above lower priority algorithms even though they are not the best candidates to solve a problem under certain circumstances, and the ability to change priorities of the algorithms according to the latest system status and performance so that algorithms are executed in an optimal order and in a timely manner.